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Re: Repairing delaminated glue-lam beam

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Thor,

        I suspect that you might be right about the problem being present during
manufacturing.

        One possible solution you might consider is adding one layer of 1.75x14
MicroLam beam on each side of your gluelams.  I would recommend that you sand
off any paint, etc. on the sides of the gluelams and glue the new MicorLam beams
in place with a liberal application of an appropriate glue (PL400 comes to mind;
but there are probably others) in addition to any mechanical fasteners you might
choose to use.  Injecting glue into the existing delaminations would probably
become unnecessary; but I would probably opt to do it anyway (I like overkill in
situations like these anyway).

        Hope this is helpful.

Regards,

H. Daryl Richardson

"Thor Matteson, SE" wrote:

> I seek comments on the repair of at least one four-year-old delaminating
> glue-lam beam.  There are two beams in question--both are 5-1/8 x 13-1/2
> 24F-V8, spanning continuously over a center post.  The portion that is
> delaminating  the worst is about five feet from one end;  there is a gap
> between the bottom lamination and the remaining beam.  This gap is over half
> the width of the lamination at its widest, and extends for about four feet
> along the beam.  The span with the worst delaminating is about 22 feet.  The
> beam supports a roof  in a house about 4 miles from my house, and I know
> that it has not gotten its full snow load in its short lifetime.  This beam
> and its twin have several other areas where glue joints appear to have
> separated very slightly.  To me this indicates problems during fabrication.
>
> AITC   Technical Note #14 states that before one repairs a delaminated
> joint, one should rule out causes such as poor adhesive quality, uneven
> surfacing of the lamination, inadequate adhesive curing or improper
> temperature, etc.  These questions seem fine if you are inspecting beams
> coming out of the fabrication line so you can save the NEXT beams to get
> built, but for a beam that is already in place, I do not understand why the
> initial cause during fabrication would affect the solution on chooses.
>
> The beam manufacturer will be presenting proposals to the Owner to repair
> the beam, and I promised to submit the problem to the SEAINT brain trust for
> comments.  Didn't find anything in the Archives.  Naturally I have advised
> them to get a written statement from the manufacturer that says the repair
> will last for the life of the structure, and that I will need a copy of that
> statement for our files.
>
> Thanks for any suggestions or comments--
>
> Thor Matteson
>
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